C ++中的fabs()
C或C++库函数doublefabs（doublex）返回x的绝对值。x-这是浮点值。此函数返回x的绝对值。以下是fabs()函数的声明。
double fabs(double x)
以下示例显示了fabs()方法的用法。
示例
#include <iostream>
#include <cmath>
using namespace std;
int main () {
int a, b;
a = 1234;
b = -344;
cout << "The absolute value of " << a << " is " << fabs(a) <<
endl;
cout << "The absolute value of " << b << " is " << fabs(b) <<
endl;
return(0);
}输出结果
The absolute value of 1234 is 1234 The absolute value of -344 is 344